Apparatus and method for conditioning oil and gas wells



July 7, 1953 B. E. MATER 2,544,532

APPARATUS AND METHOD FOR CONDITIONING DIL AND GAS WELLS Filed Dec. 9, 1947 5 Sheets-Sheecl l Arron/vin ,4free/vin APPARATUS AND METHOD FOR CONDITIONING OIL AND GAS WELLS 5 Sheets -Sheet 2 Fra-.35.

5 4 Agg@ I B. E. MATER July 7, 1953 Filed DeO.

July 7, 1953 B. E. MATER 2,644,532

APPARATUS AND METHOD FOR CONDITIONING OIL AND GAS WELLS Filed Dec. 9, 1947 3 Sheets-Sheetl 3 W; nl @200W/Wl L w////////////V IN VEN TOR. fe/vas. M475@ Patented July 7, 1953 APPARATUS AND METHOD FOR CONDITION- ING OIL AND GAS WELLS f Bernardus E. Mater, Santa Monica, Calif., as-

signor to Baker Oil Tools, Inc., Vernon, Calif., a

corporation of California Application-December 9, 1947, Serial No. 790,574

14 Claims. (Cl. 166-20) The present invention relates to oil and gas wells, and more particularly to the conditioning of flowing wells to initiate production, in the case of new well completions, or to reinstate'or increase production, in the case of wells from which production had been Ypreviously obtained. In the completing of a new well or cleaning vout of a flowing well, killing, of the well is often resorted to in order to -prevent the well v from coming into production before the necessary surface controls have been installed. Where a liner is placed opposite the producing zone or zones, it is desirable to wash behind the liner as well as inside the liner to clean the face of the productive formation and the well bore, for the purpose of obtaining the flow'of well production to the top of the bore hole. f

In completing a new well, the well bore is ordinarily full of drilling mud, which must be removed before the well can be placed on production. The liner is runvin the well on a tubular string to the desired location, and the outside of the liner then washed with water or oil until clear returns are obtained. Where formation pressures are high, the well may come into production during this operation, necessitating relling of the well bore with drilling mud to oifset the pressure, which is referred to as killing the well. Special devices 'can then be installed at the surface to permit a re-washing operation to take place and placing of the well in producy tion with the high formation pressure under effective control. For that matter, such devices may also be installed originally to control the well. Regardless of their time of installation, these special devices form a permanent part of the well apparatus, representing a costly investment in equipment. Although the special,V permanently installed equipment is effective in enabling a new well to be completed under high pressure conditions, it cannot thereafter be used to recondition, or clean out the well after the latter has been placed in production. As a result, the well must be killed by pumping in drilling mud or water, to permit removal of the special equipment and its modication or re-adaptation to the cleaning out process. Since most wells require cleaning out one or more times during their flowing life, it is readily apparent that repeated killing may be required, with the attendant hazard of sealing off the producing zones and plugging of the liner or casing perforations, which permanently'affects the well production. -In addition, the cost involved is very substantial.

Accordingly, it is anr object of the present invention to overcome the aforenoted disadvantages 'by enabling proper completion of a well, and

its subsequent cleaningl out orl reconditioning,

to take place without the necessity for killing the well. 1 l A further objectvof the invention is to complete a` well through use of equipment which can Valso be utilized for subsequent cleaning out operations without requiring the well to be killed.

Another object of the invention is to decrease the amount of equipment remaining in a iiowing well after its completion and placement yon production.

Still another object of the invention is to provide a well installation capable of use. in both completing and reconditioning a flowing well kwithout killing the Well, and which may be retrieved for usein another well, if desired.

This invention hasother objects which will become apparent from a consideration of the following description and the apparatus shown in the drawings accompanying and forming part of the present specification. This apparatus and method will now be described in detail to illustrate the general principles of the invention, but

it is to be understood that such detailed description is not to be taken in a-limited sense, since the scope of the invention is best dened by the claims appended hereto. n

Referring to the drawings: Y

Figures la and 1b together form a longitudinal elevational and sectional view of an'apparatus in a well bore, with the parts in one operative position, Fig. 1b representing a lower continuation of Fig. 1a;

Fig. 2 is a View similar to Fig. 1b, disclosing certain parts in another operative position;

Figs. 3a, 3b and 3c together form a longitudinal elevational and sectional View of the well bore, with the parts in still another operative position, Fig. 3b forming a lower continuation of Fig. 3a and Fig. 3c forming a lower'oontinuation of Fig. 3b; A Y

Fig. 4 is anv Venlarged longitudinal section shoe through one or more productive zones I3, Y

from which flowing well production is to be obtained.

In order to prevent possible sloughing in or sanding of the bore well, it is desired to place a liner Iii opposite .the producing formation I3. This liner may be of any suitable type, such as a wire-wrapped, slotted, perforated, or gravel packed liner portion I 4a coupled to the desired length of blank pipe Idb. Usually, the lower' end of the liner has a set .shoe I5 'threadedlytor otherwise secured to it, there being a liner hanger i6 attached, in a known manner, to its upper end. The liner hanger, as is wellknown, serves to support the liner I4 from the casing string IU, with the perforated portion Ida. of the liner disposed at the required location4 oppositethe pro1 Valiner setting tool I9, which forms an essential part of a tubular string 20, of drill pipe or tubing, running to the top of the well bore. `yThe tubing string also includes a` portion depending from the setting tool I9 and running through the liner I4 for threaded engagement with theset shoe I5. This threaded connection preferably, and

,.usually, consists of lleft hand `mating male and rfemale threads 2|.

The set shoe I5 includes an upwardly closing e .anddownwardly opening'poppet valve 22, whose conical head moves upwardly into engagement with a companion seat 23 lin the body 2li of the shoe. Such engagement occurs under the influence ofv a helical spring 25 surrounding the valve stem 25 and bearing against the head* 3 cludes a rubber packing elementz54,`which is sub- 22 and also againstv a spider portion' 21 of the shoe body. When the lower end of the `tubing string 2i) is threaded in the shoe I5, uid pumped down the tubing string opens the valve 22 and passes down around the spider 21 for discharge through a plurality of ports or passages 28 in the shoe, thence flowing upwardly through the annulus 29 around the liner I V In order to facilitate unthreadingor'disconnection of the lower endofthe tubing string' 23 from the set shoe I5, an expansion joint'll is mounted in the tubing' string,*preferably immediately above the shoe. This expansion joint (see Fig. 4) includes an inner mandrel' S'I'connected to a sub 32, which can be threaded into the shoe. The mandrel is telescopedwithin an outer barrel 33 connected to a collar 34 coupled toan adjacent section of tubing. 'The mandrel and barrel are slidable with respect to each other, leakage between the interior and exterior of the tubing string being prevented by suitableV side seals 35 on a mandrel'headS engaging the inner wall of the barrel 33. Y

In addition to the telescopic relationship between the mandrel and barrel, Vrotation of the barrel 33 is transferable to themandrel through.-

one or more internal splines 3'! 'formed on the lower portion 33a of the barrel, which are engageable with companion external' extended splines or keys 38 on the mandrel. It'is apparent that rotation of the barrel 33 for the purvr75 seat 60.

pose of unthreading the sub 32 from the set shoe I5 is transmitted to the mandrel 3| by virtue of the driving connection that can be effected between the splines, 37, 38.

The upper end of the casing string It is constituted byaftubing headl 39 from which one or l more 'iiowlinesi mayfextend ,(see Figs. la and 3a). Flow through these'lines is controlled by suitable manually operable valves ISI. For a l purpose to be explained hereinafter, an auxiliary casing 42;which' can be of comparatively short llength v(20 feet to 40 feet, for example), is mounted within the upper end of the casing, bering'supported bythe tubing head 39 in any suit l .able manner, asby attaching its upper end to a tapered ring 43 fitting within a companion downfward'ly and inwardly tapered portion 33a of the tubing head. The lower end 42a of the auxiliary casing is preferably beveled or iiared outwardly,

there beingv a plurality of ports or circularholes` All disposed in the auxiliary casing at a convenient 'point above its beveled end. Y

' The 'apparatus disclosed in the "drawings furvther includes atubing'fha'ngerl 45, which forms '25 'component part ofthel tubing stringZ, being connectedv therein 'atfa predeterminedpoint along lits? length. L'Ihe `upper endV ofthe' tubing hanger 'has avnip'ple 4'3`secured toit, whose terminal' -is provided with a left-hand thread 4T adapted 'to l' bel received within a mating left lhand 'thread of a collar secured to-'theportion 20a. of the tubfing 'stringi-'29 thereabove'.

The Vupper'portion'20ct' of`v the tubing string ex- Vvtends through a master vgate' valvef'l-lg 'secured to 3:, the' tubing'hea'd 39 iin-fany suitable manner, as through use of'screws 'or'studs' 50 passing'through their opposed langes'5I,52l Theupper portion extendsalso Vthrough a'fpressurefco'ntrol unit or vblowout 'preventer153 suitablysecured to theupu) VVper portionlof thegatevalveWId This' blowout preventer may be 'off'any 'desired type, suchas that described in'lth'e pate'n't'ft'o i :M.=Kilmer, jdr., 1,930,361, patented October f *10; 1933, .for 'Contractible andilllxpansible"K/'ellA Packer. It: in-

-jected toe'xternal 'pressure torcauseit to'close'inwardly upon'the'tubing string20a. Fluid under pressure necessary for the' actuation of Ythe'pressure control unit'53 ,canv be supplied througha suitable inlet pipe threadedinto the body-of --the Iunit.

'.The upper portion-.of thetubing Vstring'ZIlifurther "includes-a. tubing 'oat collar 55, to `prevent "upward vpassage of'ifluidsthrough 'the tubing y.: string. "This float collar-may Vassumel various ad"'forrrls. As"particularlyfshown'lin Fig.`6, it con- 'sis'ts of `anfoutervcollar 5'lfwhcseends are threaded to adjacent tubing sections 58, 59 to hold them in `spaced relation, there'zbeing la valve\ seat Iii)` "threadedinfthis'collar'portion /Avalve head-6I mis-movable upwardly into engagement Vwith the tapered. surface: of-the -seat to `close the valve against upward now fluids underthe influence of pressure' in the tubing string below the float l collar-56. The'valve vheadfis also moved upwardly blbya, helicalspringiSZ surrounding a valve stem 1 63. The springengajgesa guide 64 extending up- `vwardly from theseat 60, and one or more nuts .'threadedonthe stem.V v.Fluids under pressure can beA pumped down -the ytubing string-.2!) through the fiioat collar 56, -passing through side-apertures Y 66iin theextensiorrd and around thev valve stem 63','1 unseatingythe head ,6I- 4and .passing down Y through the tubing string below the tapered The tubing hanger 45 includes a suitable packing S1, such as a packing sleeve, which inherently tends to assume a retracted position,`but which can be foreshortened and expanded radially into engagement with the inner wall of the auxiliary casing 42, with which it is designed to cooperate. The tubing anchor further `includes an expander 68 below its packing, having downward and inwardly inclined surfaces @8a. cooperable withcoinpanion surfaces on a plurality of slips 69 adapted' 'packed-off? condition within the casing 42.

'6 auxiliary r`vfIf desired,the tubing hanger 45 may be set temporarily inthe auxiliary casing 42 to lsupport the'tubing stringv therebelow and the liner I4 "'attached'to itwhile'the master gate'valve 49 and pressure control unit 53 are installed. Thereafter, the remaining upper portion a, 6I, 56'of `fthe`tubing 'string can be inserted through the y last two-mentioned units 49, 53, and the collar-48 n threaded'ontothe companion nipple 441. `The to move the tubing string in a downward direction. In addition, the tubing anchor should Vinclude preferably the retractable 'packing 6l. One form of packer which can serveas a tubing hanger is described in the patent to R. C. Baker, 2,368,400, granted January 30, 1945, for Releasable Well Packer, which can be inverted from the position shown in theI patent to the one disclosed in'zthe present drawings. Since the specific structure of the tubing hanger forms no part of the present invention, further details need not be given in the specification since they may be found in the Baker patent referred to above.

Following completion of the drilling operation to form the lower portion of the well bore below the outer casing string I0, which runs through the productive zone I3, the drill pipe and drill bit are pulled and the liner is arranged for running in the well bore. The set shoe I5 isk threaded on the lower end of the liner I4, which is attached to the upper end of the liner hanger i6. The tubing string 20, with the liner hanger setting tool I9 and expansion joint 3i! incorporated therein,` is then extended through the liner I4 and the leftv hand sub 32 threaded into the set shoe. This conibination is run through the well casing I0 by means of the tubing string 20 and the linerhanger slips Il set temporarily in the well casingfat a convenient point'below the depth at which the lower end of the auxiliary casing 42 is to extend.v

This auxiliary casing may then be placed over the tubing string 20 and run in the casing- I until its supporting head 43 is received within the casing head 39. I provided on the supporting head for engagement with the tubing head 39, in order to prevent leakage therebetween.

The liner hanger slips Il are then retracted and lowering of the liner I4 continued. The tubingv hanger 45 is incorporated in the tubing stringat a .predetermined location, with'its left hand threaded nipple 46 secured to the companion threaded` collar 48 on the adjacent tubing section thereabove.

l53 when the tubing hanger 45 is'anchored' in:

Suitable sideseals 43a may be Of course, the tubing hanger parts 6.1,.. 69 are in retracted position, to allow the entire "When the lliner landing depth hasr reached, the tubngjstring 20 is manipulated to tubing anchor 45 can then be released to place its packing 61 and slips 69 in retractedpositions, these elements being locked in theirretracted positions. j The entire tubing string 20 vmay now be lowered to place-the liner I4 at its'desiredloca- "tion in the well'bore opposite the producing zones l 3,.r -Whenin such location,- the tubing hanger 45 is disposed below'the auxiliary casing 42 and well within'the main casing String I0.

been

' set'the liner hanger slips I I in the main `casing. I0, thereby supporting the liner I4 fromthe casing string (see Figs'. 1a. and 1b) At this time, however, the liner packing I8 remains in retracted position. *Washing fluid, such as water or oil, can

' now be pumped down the tubing string 20, passing outwardly throughithe ports and passages 28 in the set shoe 'I5 for upward flowing along the exterior of the-liner- I4 and along the face of the formation I3. Y This washingl fluid passes upwardly through the annulus between the liner I4 and casing string IU A,and the' annulus around tubing string 20, proceeding throughthis latter annulusand through the space between the main casing string Ip' and auxiliary casing 42 for outward passage through the pipes Mlfconnectedv to Vthe tubing head 39.'

Irhirir'ig 4thisl washing4 operation the pressure controlu'nit 53 is closed,.to ensure passage of the "returns out through the lines 4Q to the mud pit for disposal. The washing operation is lcontin-l ued, in the .manner described, until clear returns are obtained at the surface, or until the Well starts producing for a suiciently long periodto removeall mud from the formation wall and the vannulus around the liner I4.

During the aforementioned washing operation,.

the liner hanger packing I8 is retracted, to direct upward now of the substances through the annulus around the liner I 4. After the washing operation onthe outside of the liner has been completed, the linerhanger I6 is packed off by expanding its packing I 8 against the casingy I0, in a vknown manner. The entire tubular string 20 is then rotated to uns-'crew the sub 32 from the set Vshoe I5, the tubing string then being elevated slightly to position the sub slightly above the set shoe (see Fig. 2),. rWashing fluid may then be pumped down the tubing string 20, passing out of 'ner-'as the fluid employed in its lower end Aand nowing upwardly around the tubing string through the inside of the liner I4,

sincey outward'iiowing around the exterior of thev "linerisressentially prevented by the expanded tubing string and'liner, and thence upwardly through the annulus between the casing string I 0 and' tubing string 2D, flowing outwardly throughA the lines 40 to the mud sump, in the same manwashing the outside of the liner. I

...the well is under control.

AThe tubing. string yis next elevated to locate the tubing hanger 45 inside the auxiliary casing42.

vas disclosedin; Fig. 3a,.theexcess tubing inthe `string abovethe. pressure control funit53 being removed as the tubing is pulledv from Vthewell j bore'. vThe tubing string-is manipulated -toffset` the V `tubing hanger slips 169" and packing 61 .against the auxiliary'casing'42fin order `to support-the weight of the -fdepending tubing -fbelow 4the rhanger 45.

controlunit 53after the tubing hanger has been Y set infipacked-oi condition within the auxiliary casing 42. A line-`|2 with a control-valve 13 therein, can then be connectedto the reliefvalve, .theV line running to thepit. or sump. Afterthe ltubing hanger 45 hasbeen anchored to the-auxiliary casing-42,'the relief valve is opened by opening the valve 13, and the wellV allowed to flow through the tubing 'to relieve its internal pres- If desired, the. lines 40 connected `to the tubing head 39 can be closed when the `relief valve l'II is open, orthese lines`49 may also remain-open, Iin order to substantially. equalize-the pressure internallyandexternallyof the tubing string.

The tubingstring 26a above the surface connections49,r53 is then-rotated to the right-to unscrew the landing nipple collar 48from the 4fishing nipple-46 (see Fig. 3a). The upper por- `Vtion-Ztlaof thetubing string isV then elevated until the landing nipple collar 48 is disposed immediately above themaster gate valve 49 and immediately below the pressure control unit 53. .The master gate valve 49V can then be closed, to permit the tubing-string yportion 20a thereabove 1 to vbe removed completely through and from the pressure control unit 53.

valso be` removed andthe usual surface controls -installed for producing the well.

The latter can then l, During all of-.theoperations described-above, In :the event thatthe displacement of the drillingmudandithe twash- .ingof the formation cause the well to start prolducing, such productive flow cannot .pass .up-

-warclly through thev tubing-string because of the upward closing of thevalve 6I in the tubing float collar 56. The-only flow path for the-well productionand washing vfluid is through the annu- .lus between the casing string -I Il-and liner I4,- and between vthe casing-string and tubing string- 20,

fromV where Athe flow proceeds through rthe-.lines 4I! connectedfto the tubing head. If .the flow rate is too high. .these latter lines may be closed com- .pletely by their valves'fliLjor partially throttled.

During the elevation of the tubing stringfZIl At@ place the tubing hanger 45 within the auX- 'iliary casing 42; the well is still under fullconv.trolsince the pressure control unit 53 can-'be readily packed off around the tubing stringv by introducing fluid under pressure through the line- 55.- `At the sainev time, thetubing `float collar 56 `prevents-upward fiowofuids, andthe valve Y* or valves 4I controlling the tubing headlinesl 49 can-besuitably manipulated to vmaintain approf priate -well control.

During unscreWing-"of the'landing collar 48 from-the adjacent nipple 46 Yconnected to' the tubing hanger`45, thewell'is still under control,

which is also true of the removal of such discon- `the auxiliary casing 42. quent connectionof the surface controls` permits j ment'of the gate valve 49.

`which isthen closed,.as described above, to completely shut olf the wellow upwardly through Of course, the subsethe VWell to be produced in the desired manner.

The tubing hanger 45 is located in the'tubing string 29 -at such Ypoint as to ensure the placing of the lowermost end of vthe tubing string at the desired depth in the well casing I9, at which it is intended for the well production to enter-the tubing string during normal operation of the well. This point will ordinarily be above the `perforated liner I4, `although its best location location above the pressurecontrol unit whenr the tubing hanger 45 is set in the auxiliary casing 42. Y

In the method of `completing an oil well described above, the tubing hanger 45, liner setting ltool` I9 and expansion joint 3i) are left in the producing string 20. Because of the characteristics of these items of equipment, they'can be employed. subsequently in cleaning out operations, to bring the flowing well back into production, orto increase its declined production due to sanding or partial sanding of the well. lSuch cleaning out operations can take place without the necessity of killing the well.

In performing Va cleaning out operation, the master gate valve 49 is closed and the pressure control unit 53 is installed in place. The upper portion 26a of the tubing string heretofore used, including the landing nipple collar 48, relief valve 6I and tubing vfloat kcollar 56, is then inserted in position above the pressure control unit, the landing nipple being moved through pressure control unit 53 to a point above the movable ele- The pressure control unit is actuatedto produce engagement of its packing element 54 with the exterior of the tubing string. The gate valve 49 is then opened to' allow'entry of the tubing string portion 20a,

' into'. theauxiliary casing 42 to a point adjacent the nipple 46. The tubing string is then rotated to the left to thread thelanding nipple collar 48 onk to the nipple 455N extending from the tubing hanger`45.

The tubing stringZIla is then manipulated to retract the tubing .hanger packing 61 and slips '69,fand1to lock them .in'retracted positions, as

fully describedin the .Baker patent above referred to. The entire tubing string 29, includall portions below the tubing hanger 45, can then be lowered through the well casing I0 and vliner I4 to -the point where the sand can be washed out from the inside of the liner by pumping washing fluid down to the tubing string. If

^ necessary, the left hand sub 32 at the lower end of thel expansion joint 30 can be re-threaded into the set shoe I5 to enable washing fluid topass Y behind the liner I4, cleaning the face of the formation I3, and ensuring its full production once again.

After the washing operation has been completed,..the tubing string v2Ilcan be elevated, the

' tubing hanger 45 again set Vin the auxiliary casing 42, the portion 2llaof the tubing string in- :cluding the tubing floatcollar 56 and 4relief valve 'I I againrremoved through -the pressure control l unit 513, themastergate valve ,49 closed, the pressure control unit'53 removed, andthe surface connections re-installed. In View of the retrievability of the tubing hanger 45 through retraction of its slips [i9 and packing 61, the tubinghanger, liner. setting tool I9, expansion joint `t, and all o f the other tubing sections dependingirorn the tubing-.hanger 45, can be removed :from thewellbore whenever desired, as when after the well has ceased flowing. They can then be installed in another well, thus allowing the equipment to be used for its full operating 1ife.

`It is to be noted that new wells can be completed and placed on production without killing the well whenever the tubingstring is to be removed from the well bore. Complete control of the well is maintainedduring its'entire conditioning, avoidanceoi pumping drilling mud into' the well bore to kill the wellpreventing possible diminution of subsequent'well flow through mudding off of the producing zones and plugging of the liner perforations. The time for completely washing out the well and placing it onproduction is reduced considerably, vand the quantity of equipment remaining in the well is also substantially less than heretofore required.

After the well has been on production, it can be reconditioned Without killing the well with mud or water. Washing operations can take place with oil and the I,equipment withinthe well casing can be readily used 'in .the reconditioning operation, during which the well isun'der'complete contro-l at all times.

' The inventor claims:

l. The method of conditioning'ia well bore; which includes connecting ythe 'lower portion of a linervto a tubular string and lowering `saidliner on said tubular'strin'g through casing in said well bore; hanging said'liner from saidcasing without packing 01T the space between said liner and casing; while said liner is hanging ,from said casing pumping washing 'iiuid down saidtubular string and laround said liner; thenpacking the space between s aid linerand casing string whilesaid liner is hanging from said casing string; then dis,- connecting said tubular string fromsaid liner; pumping Washing fluid downsaidtubularstring for upward now within said liner; thenhanging said tubular string in said casingjv disconnecting the upper portion of said tubularstring above its hanging location in said casing; and withdrawing said upper portion from said casing. 1

, v2. The method `oi conditioning ,a well bore: which includes providinga casing string in said well bore, a valve at the upperend otsaid string, and a pressure control unit above saidvalve; connecting the lower portion of a liner to ai tubular string and lowering -said lineron said tubular string, the tubular stringextending through said valve and unit; hanging said liner from said case ing while said liner remains connected to said tubular string without packing off the space bef` tween said liner andcasng; While said liner is hanging from saidcasing'pumpirig'washing fluid down said tubular string for upward flow around said liner; then packing the space between said liner and casing string while said liner is hanging from said casing string; then,disconnecting said tubular string from said liner; pump-ing washing fluid down said tubular string for'upward flow within said liner; Ithen hanging said tubular string in said -casingfstring;` disconnecting'the upper portion .of lsaid tubular string yabove its hanging location in said casing string; withdrawing 4said-upper portion from said casing string to locate the lower end'of said disconnectedupper portion between said valve and unit; and closing said valve.

v3. The method of conditioning a well bore:

which includes providing a casing string 4in said bore, a valveV at the upper end of said string, and

a pressure controlunit above said valve; connecte.

ing the lower portion of a liner to a tubular string and lowering said liner through said casing string on said tubular string, said tubular string extend-v ing through said valve and unit; closing 'said tubularstringagainst upward low of iiuid there-A through; hanging.- i said liner from said casing string while said linerl remains connected to said tubular string without `packing off the space bee,

pumping washingluid down said tubular string for upward flow within saidliner; then hanging said tubular string in said casing string; disconv nectingthe vupper portion oisaid tubular string aboveits hanging location in said casing string; withdrawing said upper portion from said casing string to locate the upper end of said disconnected upper portion between said valve and unit; and closing said valve.

.iAppa'ratusifor conditioning weils: which in.- clu'des'a liner j atubular string extending through s aidtliner and attachedto the lower' portion of saraimagens-tubular "sn-ing hating a rei-,new able tubing hanger incorporated therein and dis-,- posed above said liner in spacedrelation thereto j, a casing to which ,said hanger can be anchored; said hanger having an expansible andretractable packing embodied therein movable laterally into and out of engagementwith the casing for sealing said hangerwithin said casing andfpreventing nuidflow along the exterior of the hangerfua valve 'through whichsaid string extends; and a pressureycontrol unit above said. valve through which saidstnng extends. l

5. Apparatus'for conditioning wellszWhich includes 'a main casing string;V an auXiliarS casing string'rdepending within said main casing string toasubstanti'al extent from the upper end of said main casing string; a main valve connected to the upper end of said main casing string; a pressure controlunit above said valve; a liner adapted to be ,lowered through said main casingastring; a tubular stringy connectedto said liner and extending through said valve andv unit,` said tubular string having a retrievable tubing hanger incorv porated therein for anchoring in said aum'liary casing string, said hanger including eXpans-ible and `retrac't'aol'e slip means engageable with said auxiliary easing string and also an expansible and retractable packing engageable with .said auxiliary 'casing string. k

6. Apparatus for conditioning wells: which iin-7 c ludesa main casingstring; an'auxiliary casing string depending Within said main casing string to. a substantial extent fromthe upper endof said main casing string;v a main valve connected t o the ,upperendof' said main lc asing string; a pressure'l control unit above said valvea Iliner, adapted to be lowered through said main casing strin g ,j ,a/tubular'string connected to said liner and extending` through said valve and unit, said tubular string having a retrievable tubing hanger incorporated therein for anchoring 'in saidY auxiliarycasing string against ydownward movement, said tubing hanger having an expansible and retractable packing for sealing engagement with said auxiliary casing string, and a check valve in said tubular string above said hanger.

' In apparatus for conditioning wells: a liner hanger secured to said liner and having slipsV and packing means for engagement with a wellicasing; a tubular string having'a retrievable tubing hanger incorporated `therein above said, liner hanger'and a -setting `tool connected to said liner hanger; said -retrievable tubing hanger including expansible 'and retractable Slipmeans and expansible and retractable packing means 'movable laterally 'into and out ofA engagement with the well casing;y and a valve in said tubular string above said hanger.

/8. 4Apparatus for conditioningwells: lwhich includes a main casing string; an auxiliary-casing string depending within said main casing 'string to a substantial extent from the upper end of said main casing string; a main valve connected tothe upper end of said'main` casing string; a

pressure control unit Vabove said valve; a liner adapted to be positioned below' said main casing string, said linerr having aset shoeV on its' lower end; a tubular string connected to said set shoe and extending through said main valve and unit; a'liner hanger secured kto the upper end of said liner, said liner hanger'having slips and packing means both engageable with said'main'casing; a retriev'able tubing hanger incorporated in said tubular string for AAVanchoring linjsaijd auxiliary casing'string; said Vretrievable tubinghan'ger including expansibleand retractable slipmeans engageable with said auxiliary casing string and expansible and retractable packing Vmeans engageable with vsaid auxiliary casingstring; a setting tool incorporated 'in `said tubular string'for connection with said liner hanger; and a downwardly opening check valve insaidtubular'string above saidvtubing hanger.

9. Apparatus for conditioning wells: which includes a main casing stringy'an auxiliary casing string 'within and at Ythe upper end'of said 'main casing string; a main valve connected tothe upperend of said main casing string; a'pressure control unit above said valve; a liner adapted to be lowered through said 'main casing string; a tubular string conn'ected'toA said liner and Vextending through said valve' and unit, Asaid'tilbular/string having a'retrievable tubing'h'anger incorporated therein for anchoring in said 'auxi1iary casing string; a iiuid flow line "communicating with the-annulus betweensaid main and/auxiliary casing strings; said auxiliary casing stringextending substantially belowl said fluid floW'line; and -means providing a lseal above said' fluid flow line between said main and -auxiliary casing strings. l

410. Apparatus for conditioning wellsz' which includes a main casing string; an auxiliary casing string within and at the upper end 'of Vsaid'rnain casingfstring; -a Vmain valve connected to the upper fend of said main casing string; 'a pressure control unitabove and communicable with said valve; -a liner adapted to be lowered through said main l -casingstring; a tubular string connected to said liner'and extendingthrough said valve andrunit,V said tubular string having a retrievable tubing hanger incorporated therein for anchor` ing in. said auxiliary casing string,l said hanger havingan expansible and retractablepacking fori sealing with said :auxiliary casingestringj *and aiuidfow linefcommunicatingwith atheannulus between said Lmain ande aux iliary=-`casingfstrings said auxiliary casing stringvcxtendingsubstantially below-said=` fluid ow'line; and means providing -a 'seal abovesa-id -Y'fluid flow line between saidA main-I 'and'fauxiliarycasing strings.

11. 'Apparatus 'for conditioning wells: which includes amainY casingrstring; anA auxiliaryL casingjstring 2withinandrat""the.supperend of said main casing string; 'af-main* valve"v connectedr to theupper end-of-sa'id"main-casing string; a pressure'control unit aboveand communicable with said valve; a liner adapted to be'lowered through saidijmain casing" string; Va tubular stringconnected to said ,linerfand extended through said valve and Vunit,A said-'tubular''string having` a retrievable`tubing'ghangerfincorporated therein for anchoring" in saidauxiliary c'a'singstring, and also a checkvalvefinsaid tubular'string above said" hangengsaid; hangerw y'having an expansible and retractable packing 4for sealing -`*with said auxiliary` 4casing `string; 'and ia'- fluid Anow line communicatingfwith the annulus between lsaid rnainil and auxiliary casing strings; said auxiliary casing string `extending substantially below said fluid'fflow lline; and fmea'nsproviding a ,seal above said uid ow'line betwe'ensaidmain and auxiliary Icasing" strings. v

l2. Apparatus 'fforrcouitioningj wells: which includes a mainpasing string; an auxiliary casing stringwithin'andi'attheupper-end of 'said main casing-string; a 'main'valvebonnected' to the` upper endof said main casingstring; a' pressure control unit above said valve; alin'er adapted to'be loweredthrough said maincasing string ;l a -tubular 'string connected :to'said liner and extending through said 'valveand unit; said tubular string having a V'retriev'abletubing 'hanger Vincorporated therein"`for anchoring'in'vsaid' [auxiliary casing string against""downward movement,` said tubing hanger l"having 1anexpansible zand retractable packingor sealing -engagement with said auxillary vcasing stringfa'fcheckvalve `in said tubular string aboves aid hanger; Jand afiiuidfnow line communicatingcwith*the VAannulus between 1 said mainand auxiliar-ycasingfstrings --said auxiliary casing stringeextening,substantially below said fluid ifiow Yline; iandfmeansi providing '-a seal above said iifuidfow line between saidmain land auxiliary #casing strings.

li3. Apparatus 2for -conditioning -f wells: which includes Lafmain -casing string f an--auxiliary casing string within;la'nda'at'ltheV u-pperfenduofy said main casingstr-ing-a` main-'valve connected Vto thefupperf 'end cffsaid main casing stringya-pressure "control unitfk aboveland p communicable with said-valve; av liner adapted to -be loweredthrough saidxnain leasing f-string; ya' liner-hanger secured to Y*said `'liner for supporting said liner `Vfrom said m'ain -casing A"stringlbelow 'sa-id auxiliary casing string;-Latubularfstring-connected to said liner andextendingtthrough said valve andunit, said tubular strnghaving f a retrievaole tubing hanger incorporated vtherein for anchoring vin saidV auxiliary casing fstring 4against'Y downward movementgsaidtnbing.hanger having an expansibleand yretract'able ,packing for sealing engagement with :saidgauxiliary l casing. l string, a check valveY iny s aidf, tubular. string.; above said ha-nger; and: affiuidflow -li-ne .gzommunicatingwith 1 the annulus between.saidrmainand-:ailxliary casing strings; p said auxiliaryf basin-gq? string extending substantially :below 1 said iuididlowi'line; fand meanslproviding-.s arsseal .fsabove said 'fnnid ffo'w 13 line between said main and auxiliary casing strings.

14. Apparatus for conditioning wells: which includes a main casing string; an auxiliary casing string within and at the upper end of said main casing string; a main valve connected to the upper end of said main casing string; a pressure control unit above said valve; a liner adapted to be positioned below said main casing string, said liner having a set shoe on its lower end; a tubular string connected to said set shoe and extending through said main valve and unit; a liner hanger secured to the upper end of said liner, said liner hanger having slips and packing means both engageable with said main casing; a retrievable tubing hanger incorporated in said tubular string for anchoring in said auxiliary casing string; a setting tool incorporated in said tubular string for connection with said liner hanger; a downwardly opening check valve in said tubular string above said tubing hanger; and a uid flow line communicating with the annulus between said main and auxiliary casing strings; said auxiliary casing string extending substantially below said fluid flow line; and means providing a seal above said fluid flow line between said main and auxiliary casing strings.

BERNARDUS E. MATER.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,852,716 Grinnell Apr. 5, 1932 1,921,115 Brown Aug. 8, 1933 2,111,793 Lee et al Mar. 22, 1938 2,157,964 Mueller May 9, 1939 2,189,701 Burt et al. Feb. 6, 1940 2,211,845 Brown Aug. 20, 1940 2,277,380 Yancey Mar. 24, 1942 2,328,840 OLeary Sept. 7, 1943 2,359,710 'Collins et a1 Oct. 3, 1944 2,368,400 Baker Jan. 30, 1945 2,442,544 Johnson June 1, 1948 

